DE1538709A1 - Rotor for an electric machine - Google Patents

Description

DIPL.-ING. HELMUT MSSLING 63giessen, June 18, 1969

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DIPL.-ING. RICHAR DSCHLEE phone; Coeini 73 * 00

PATENTANWÄLTE M / EP 8819

i-llmänna Svenska EIektriska Aktiebolaget, Ya 3 t er as / Sweden

Rotor for an electric machine

The invention relates to a rotor for an electrical machine, specifically a rotor with a rotor ring which is axially parallel supports lying to the rotor axis, which together with end plates lying one behind the other in the axial direction, a hub and several spokes form a rigid rotor frame. The carriers mentioned are each provided with a fastening arrangement provided which is in engagement with an axial groove on the inside of the rotor ring and a free radial expansion of the rotor ring. The invention further relates to a method for producing such a rotor.

The rotor ring of an electrical machine is strong in operation Subjected to centrifugal forces. In order to give the rotor a structure that is sufficiently dynamic at different speeds is stable, the rotor ring has hitherto been fastened to the rotor frame under strong radial prestress by the ring shrunk onto the frame or with radially directed pressure

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loaded rods. However, such a construction of the rotor is expensive and places great demands on accuracy of manufacture and assembly.

The structure of the rotor becomes simpler if the rotor ring is arranged in a known manner on the radially inside the ring Frame is attached on the principle of the "floating rim", i.e. in such a way that the rotor ring is under can expand freely under the action of centrifugal forces. Naturally Such a rotor must have a torque-transmitting connection between the rotor frame and the rotor ring. It is also It is of great importance that a strictly coaxial relationship between rotor frame and rotor ring under all conditions is maintained.

In certain known cases in which the principle of the "floating tire" is used, the necessary coaxiality is ensured by special flexible construction elements which form a connection between the rotor frame and the rotor ring and can be designed with adjustable radial extension. Such a construction is described in British patent specification 1,007,103. In another construction, which is based on the same principle, namely the m of British patent specification $ 0 $ 906, the rotor frame and its organs for the torque transmission are machined with great accuracy after being welded together

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of the rotor frame has taken place, which along with great Precision in making the ring such a strict one. radial guidance of the fastening elements engaging in grooves in the rotor ring shows that a coaxial relationship is maintained even with maximum expansion of the rotor ring.

A rotor according to the invention is also designed according to the "floating tire" principle and has no special construction elements provided to ensure the aforementioned coaxiality. But in contrast to the construction shown in the British patent specification -jO'y 906, the rotor frame of a rotor according to the invention can be produced almost completely with a relatively low degree of accuracy and the machining of the parts that are never decisive for the position of the rotor ring during its expansion is carried out before they are welded to the rotor. A rotor and a method for its production according to the invention are therefore particularly suitable for machines that are so large that the rotor must be assembled at the installation site.

A rotor according to the invention is characterized in that the said face plates are designed with several recesses on their outer edges and between the spokes and the said supports are provided with welded-on mounting plates and are arranged in the said recesses with sufficient play, a number of mounting plates each overlap a recess and are welded to the end plates.

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The invention also relates to a method for producing the above-mentioned rotor, which is characterized in that several sheet metal segments are joined together to form said rotor Rotprring to form that the aforementioned supports are provided with welded, transversely protruding fastening plates be, -dal? the beams are processed prior to their assembly so that they fit together with the aforementioned fastening applications, and that said face plates are welded together to said spokes and hub and are mainly coaxial with the rotor ring are arranged, said carrier with sufficient adjustment play in the recesses formed in the face plates between the spokes and arranged on. Rotor ring fastened by the aforementioned fastening applications are, after which the carrier are attached to the rest of the rotor frame in that said fastening plates to the Front plates are welded on.

The fastening arrangements between the rotor frame and the rotor ring are preferably designed according to the invention so that the rotor frame .a number of bars with a U-shaped cross-section and the Rotprring a number matching the U-iTut of the guiding lines Has guide rails? In this way it is possible in a simple way that the rotor ring can expand freely radially, while on the other hand tangential? Moment forces from the rotor shaft and can be transferred to the Rptor frame to the Rotprring. Regarding the regulation the breadth of troubles. are expediently boar organs

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used, and the actual guide rails can after of the invention be composed of mutually sliding wedges. Laugh at the G-leitf, which is the radial expansion allow the rotor ring are preferred according to the invention Plastic or other inserts to reduce friction Material arranged. Polytetrafluoroethylene is particularly suitable as a friction-reducing material.

The invention is described in more detail below with reference to the drawing, which show: I ¹ Ig. 1 in a front view of a sector of a rotor according to the invention and

Pig. 2 a detail of the pig. 1 in perspective Depiction.

In the drawing, 1 denotes the shaft of the rotor, 2 the rotor frame and 3 outer rotor ring. The rotor ring is made up of a number built up of stacked sheet metal segments which overlap and are supported by a large number of axially lying bolts 4 are held together so that a solid unitary rotor ring is obtained. On the outside the rotor ring has several dovetail grooves 5 for holding the rotor poles with the Winding that are not shown in the Pigur. Bolts 4 and dovetail grooves 5 are only in a limited part the figure is fully drawn "."

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The eotor frame Ί consists of a nose ring 6 and two end plates 7 which are arranged at a certain distance from one another and which are connected to one another by spokes or plates 8.

In grooves of the rotor ring 3 on its inside are several Guide strips 9 attached. The rotor frame has a corresponding number of U-shaped supports TO, the U-grooves of which Take up guide strips 9. The guide strips 9 can be in Relation to the carriers 10 slide radially, this means that the rotor ring 3 is under the influence of centrifugal force can expand, whereby this'distance does not affect the torque transmission acts between the rotor core and the rotor ring. In order to get a good fit between the beams 10 and strips 9, one or more additional fitting wedges or filler pieces 11 are used. The fitting elements 11 can also be used to set the tangential position between guide elements and guide rails. -

With radial expansion of the rator ring 3, sliding surfaces are either between the strips 9 and fitting elements 11 or between these elements and the guide elements 10 are arranged. In the case of the G-Leitf, a friction-reducing system is used in an expedient manner Surface covering, e.g. made of polytetrafluoroethylene, attached.

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Εαη inventive rotor is expediently manufactured in such a way that that the carrier 10 during assembly of the rotor is movable in relation to the hub, spokes and end brackets Part of the Rptorgestell.es are arranged so that they are at the Assembly of the Rpiprringes and - only after this is essentially fully assembled - definitely attached to the rotor frame will. This method enables the rotor to be built up from the rotor ring. This will give the benefit won that the Rptorrahmen without too great demands can be produced in terms of precision, because you are in the critical Moment of assembly, i.e. when assembling the rotor ring and the inner part, an adjustment can be carried out. The hole for the rotor shaft in the rotor stand must of course be drilled as the last step of the assembly, but this can be done in happened in a known way.

lim during plague welding of the carrier 10 a deformation of the carrier To avoid this, they are provided with fastening plates 12 in advance. A favorable transmission of the tangential forces To achieve between the beams 10 and the rotor frame 2, the beams 10 are also protruding tangentially in advance Fastening bodies -15 provided that at the ends of the Sheets 8 are welded in place. The mounting plates 12 and Fastening bodies 15 are welded to the girders 10, before these are machined to size, so that 4I§ of the welding

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changes in shape caused by heat cannot change the final dimensions. Because the exact position of the beams 10 in relation to the rotor frame only during the assembly process is determined, it is essential that the attachment Allows adjustments. The embodiment shown with tangential fastening bodies 13 is particularly suitable for tangential adjustments and at the same time also for smaller ones radial adjustments. A recess 14, which is large enough for the desired adjustments, must of course be in the face plates 7 can be arranged at the carriers TO.

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Claims (1)

- claims; 1 . Rotor for an electric machine with an eotor ring, which is carried by axially lying supports, which together with end plates arranged axially one behind the other, a babe and several spokes form an s-rigid eotor frame, are each provided with a fastening arrangement which engages with a corresponding Fut on the inside of the rotor ring and a free expansion of the rotor ring allows, characterized in that the end plates (7) with several recesses (H) on the outer edges and between the Spokes (8) are formed that the carrier (10) with welded on Fastening plates (12, 13) are provided and arranged in the recesses (14) with ample play and several fastening plates each overlapping a recess (H) (12) are welded to the end plates (7). 2, method for manufacturing a rotor according to claim 1, with a rotor ring extending from parallel to the axis of the rotor lying beams is carried, which together with end plates, a hub and several spokes form a rigid rotor frame and each provided with a fastening arrangement which engages a corresponding axial groove on the inside of the rotor ring is and a free radial expansion of the rotor ring 'allows, characterized in that the Carrier (10) transversely protruding fastening plates (12) 909884/0736 '-10- welded on and the girders processed in this way prior to their assembly that they fit together with the fastening arrangements, that the end plates (7) with the spokes (ö) and the hub (6) welded together and arranged substantially coaxially in relation to the rotor ring (3) that the carrier (10). with a sufficient adjustment play in the recesses (14) formed in the end plates between the spokes (8) and fastened to the rotor ring (3) with said fastening arrangements (9, 11) and that then the beams on the rotor frame be fastened in that the said fastening plates (12) are welded to the end plates (7). BATH 9098 8 4/0 7 36 / 11. L e r s e i t e